This invention relates to communication equipment. More particularly, it is concerned with signal monitoring apparatus for determining the noise present in received signals.
There are many known techniques for measuring the noise present in received signals and for determining the signal-to-noise power ratio. Although these techniques are satisfactory for certain applications, many of them provide limited resolution, are difficult to calibrate accurately, and are susceptible to drifting. In addition, there are difficulties involved in employing known techniques to obtain averaged or rms measurements of the noise present.